Improvement in plates and bars for construction of plows



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WILLIAM H. SINGER, OF PITTSBURG, PENNSYLVANIA.

Letters Patent No. 108,641, dated October 25, 1870.

lMPROVEMENT IN PLATES AND BARS FOR CONSTRUCTION OF PLOWS, CULTIVATOR- TEETH, &c. 1 y

Theschedulo referred to in these Letters Patent and making part of the same To all whom it may concern Be it known that I, W'ILLIAM H. SINGER, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have inventetLa new and improved Cast- Stcel for the Construction of Flows and Cultivatorleeth; and I do hereby declare the following to be a full, clear, and exact description of the same.

This invention consists of a certain improved caststeel, when applied to the copstrnct-ion of plows and cultivator-teeth.

The said improvement lies in treating mild-tempered cast-steel, when formed into ingots or slabs in a converting-furnace, in such a mannerv as to carbonize the ingot from its surface inward to any depth that may be found preferable short of a complete carhonization, theceutral part of the ingot being left, in that case, comparatively soft or mild, and hence more tenacious than the surface.-

The object of treating mild-tempered cast-steel in this manner is to obtain a material which may be hardened in its external carbonized portion to any required extent, and at'the same time retain a mild and tenacious internal uncarhonized portion, such as will not or ck.-

Y Heretofore it has been found impracticable to harden ordinary cast-steel, such as has been used for the manufacture of plows and cultivator-teeth, owing to the fact that in hardening a great percentage of such steel warps or cracks, and is consequently rendered useless.

The steel herein described, however, does not crack in hardening, andvconsequently is peculiarly adapted dinary manner, and place it in thejconvertiug furnace,

allowing it to remain several days untilrcarbonized to the depth required. It is their allowed to'cool' 'very gradnall y, and when finally taken from the furnace is rolled into plates of the required thickness for plowsharcs, mold'boards, and cultivator-teeth,

This produccsjan article entirely different from and superior to those manufactured from iron treated in a similar way.

Having thusdescribed my invention,"

' What I claim as new, and desire to secure bv Letters Patent, is

' A plow-share, mold hoard, or cultivatontdoth, when made of solid recarbonized cast steel, whereby it has a mild center, substantially as hereinb efore decribcd.

- WILLIAM H. SINGER.

Witnesses: v

ERASTUS AGNEW, HENRY P. Form. 

